He was pushing a line with dangerous people, and that was what was lost on, I imagine, some of the audience. That's probably part of the brilliance of Sandler's casting, as it's possible to take much of the movie as a joke, and the "goons" as inept as the ones from Home Alone or some movie like that. But, they weren't. Rattner's evasions and lies become a comedy in itself, subtly, and you can miss, the real menace that is looming. That is why the last Celtics game takes on such significance, as he is REALLY pushing the lines, practically begging those guys to try him, but he can't help himself. He truly is lost in a gambling addiction, and can't see that others won't see it as a win.
Also, increasingly, the goons felt emasculated by Arno, who was coming of soft and ineffectual. He wasn't with that level of violence, he was just frustrated, but he saw the bigger picture. Those other guys didn't. There's a few lines where the main guy says "Arno, don't listen to this fukking guy anymore, come on", more than once. Arno, saw bigger picture, that he was family, and he wasn't going to kill him, but also, he could keep bleeding him, he just needed that balance of fear, to maintain credibility as a loanshark.
). As for people not liking the end, it had to end like that 
They already put up with a ton of shyt and would've done the deed long before but they were noting that too many people were around. Howard already showed that he is going to use everyone around him until they want nothing to do with which is no surprise that the only ones who want to be with him are his side chick and his kids & even his daughter is distant to him and 1 of his sons started to finding out about him cheating.
until the credits rolled.
